[flang] Handle assumed-type dummy arguments in ExtractDataRef

[klausler]

Assumed-type dummy argument symbols s are never packaged in DataRefs since the only way they can be used in Fortran is by forwarded as actual arguments to other calls. When an ActualArgument comprising a forwarded assumed-type dummy argument is presented to ExtractDataRef, it fails, because ExtractDataRef for ActualArgument only handles actual argument expressions (including variable references). Add support for actual arguments that are assumed-type dummy arguments.

Fixes #168978.

[llvmbot]

@llvm/pr-subscribers-flang-semantics

Author: Peter Klausler (klausler)

Changes

Assumed-type dummy argument symbols s are never packaged in DataRefs since the only way they can be used in Fortran is by forwarded as actual arguments to other calls. When an ActualArgument comprising a forwarded assumed-type dummy argument is presented to ExtractDataRef, it fails, because ExtractDataRef for ActualArgument only handles actual argument expressions (including variable references). Add support for actual arguments that are assumed-type dummy arguments.

Fixes #168978.

---

Full diff: https://github.com/llvm/llvm-project/pull/169080.diff

2 Files Affected:

• (modified) flang/lib/Evaluate/tools.cpp (+5-1)
• (added) flang/test/Evaluate/bug168978.f90 (+6)

diff --git a/flang/lib/Evaluate/tools.cpp b/flang/lib/Evaluate/tools.cpp
index 117b2249a9179..a0035ae330e35 100644
--- a/flang/lib/Evaluate/tools.cpp
+++ b/flang/lib/Evaluate/tools.cpp
@@ -63,7 +63,11 @@ Expr<SomeType> Parenthesize(Expr<SomeType> &&expr) {
 
 std::optional<DataRef> ExtractDataRef(
     const ActualArgument &arg, bool intoSubstring, bool intoComplexPart) {
-  return ExtractDataRef(arg.UnwrapExpr(), intoSubstring, intoComplexPart);
+  if (const Symbol *assumedType{arg.GetAssumedTypeDummy()}) {
+    return DataRef{*assumedType};
+  } else {
+    return ExtractDataRef(arg.UnwrapExpr(), intoSubstring, intoComplexPart);
+  }
 }
 
 std::optional<DataRef> ExtractSubstringBase(const Substring &substring) {
diff --git a/flang/test/Evaluate/bug168978.f90 b/flang/test/Evaluate/bug168978.f90
new file mode 100644
index 0000000000000..ffe77500aeba5
--- /dev/null
+++ b/flang/test/Evaluate/bug168978.f90
@@ -0,0 +1,6 @@
+!RUN: %flang_fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
+subroutine sub(dd)
+  type(*)::dd(..)
+  !CHECK: PRINT *, size(lbound(dd))
+  print *, size(lbound(dd)) ! do not fold
+end

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